To improve the progression-free survival in patients with high-risk neuroblastoma this trial will prolong therapy with isotretinoin to 24 months, the time window in which most relapses occur. The treatment is anticipated to be well tolerated with no increase in adverse side effects based on the benign side effect profile of patients who have received the typical 6 month treatment course. The trial will consist of a single arm of 20 high-risk neuroblastoma patients who will receive a total of 24 cycles of isotretinoin (2 weeks on treatment followed by 2 weeks of rest) compared to the historical and current COG study treatment of 6 cycles. Patients will be accrued over a 3-year period.